Sideways Strength 

If eggs are packaged vertically, it must be because they are strongest at their ends. At least, this had long been the assumption. 

When MIT engineers put this belief to the test, however, they cracked open the belief and found that eggs are far more resilient on their sides. 

“Every year we follow the scientific literature and talk to the students about how to position the egg to avoid breakage on impact,” study author Tal Cohen said in a statement. “But about three years ago, we started to question whether vertical really is stronger.”   

The study found that, by positioning an egg sideways and pressing on it, it bends a little instead of breaking immediately. Horizontally, eggs behave similarly to how a car’s shock absorbers work: They bend slightly under pressure, allowing them to absorb more energy without breaking. 

To determine which side is stronger, the researchers conducted both static and dynamic tests.  

With static compression tests, they applied a gradually increasing force to measure stiffness and toughness.  

“In the static testing, we wanted to keep an egg at a standstill and push on it until it cracked,” said study co-author Avishai Jeselsohn. “We used thin paper supports to precisely orient the eggs vertically and horizontally.” 

Researchers discovered that the same amount of force was necessary to start a crack in both places. However, there were differences in how much compression an egg could take before breaking. “The horizontal egg compressed more under the same amount of force, meaning it was more compliant,” said study author Joseph Bonavia. 

Through mechanical modeling and numerical simulations to confirm results, the study concluded that, despite the consistent force applied to the egg, the horizontal side of the eggs absorbed more energy due to their compliance. 

The researchers then performed dynamic drop tests – ensuring simultaneous release and consistent egg orientation – to confirm that the results held up in practice. Dropping eggs from various heights, they observed that horizontal eggs cracked less frequently when dropped from the same point. 

“This confirmed what we saw in the static tests,” said Jeselsohn. “Even though both orientations experienced similar peak forces, the horizontal eggs absorbed energy better and were more resistant to breaking.”